| 摘要 |
To appropriately calculate and correct the amount of phase shift in the phase component of a correlation value between a receipt signal received by each of a plurality of reception antennas and a transmission signal with minimal influence on measurement performance, and to thereby inhibit a degradation in accuracy in estimating the arrival angle of a target. The disclosed technique includes transmitting a signal intermittently according to a transmission cycle having a predetermined transmission period and a non-transmission period; receiving the signal reflected from a target with reception antennas which are selected secuentially by a switch; and detecting the target from the reflected signal. A high-frequency transmission signal attenuated during the transmission period and a receipt signal received during the non-transmission period are combined together. A correlation value between a reference transmission signal and the receipt signal in the combined signal is calculated, and the amount of phase shift in an arbitrarily selected reception antenna is calculated from the correlation value of a reference reception antenna, and the correlation values of the other reception antennas. The phase component of the correlation value of the arbitrarily selected reception antenna is corrected on the basis of the amount of phase shift. |
